I am not sure what that has to do with my post. I struggled with the understanding of “Sabbath” all my life, until I observed a real Sabbath with a Messianic congregation and THEN it became clear to me what is the purpose of the Sabbath.
The Lord does not care so much about the legalism of counting days. He gave us Leviticus so we could see what Legalism is about.
Jesus told us to apply the spirit of law to the letter of the law- and love Him with all our heart.mind and soul.
So- see what the Spirit of the Sabbath is all about. The letter of the Sabbath is not going to bring you any joy.
Shalom.
Seems like there could easily be a day or two shift such that today's Sunday doesn't perfectly align (EXACTLY some large multiple of 7 day weeks ago) with the Sunday of ancient history.